Dental-tool guard



(No Model.)

F. P. HOYER. DENTAL TOOL GUARD.

No. 594,952. Patented Dec. 7", 1 97 5 ill u I Zwremio: Emma/1 77:2162" j UNITED STATES PATENT OFFICE.

FRANK F. HOYER, OF OWOSSO, MICHIGAN.

DENTAL-TOOL GUARD.

SPECIFICATION formingpart of Letters Patent No. 594,952, dated December 7, 1897.

Application filed March 11, 1897. Serial No. 626,979. (No model.)

T0 to whom it may concern:

Be it known that I, FRANK F. Hovnn, acitizen of the United States, residing at Owosso, in the county of Shiawassee and State of Michigan, have invented certain new and useful Improvements in Dental-Tool Guards, of which the following is a specification, reference being had therein to the accompanying drawings.

It is the object of my invention to provide a guard for dental tools in which the opening through which the tool works may be varied according to the work to be performed; and the invention consists in the peculiar construction, arrangement, and combination of parts, as more fully hereinafter described and claim ed.

In the drawings, Figure 1 is a perspective view of my improvement as applied to the handpiece of a dental engine. Fig. 2 is. a cross-section on line new, looking from the rear. Fig. 3 is a front elevation of a slightly-modified form of guard. Fig. 4 is a central longi-' tudinal section thereof. Fig. 5 is a perspective View of the parts of the guard detached.

A is the handpiece of a dental engine, and

'to the handpiece A, preferably by means of a socket a on the handpiece, into which a rearwardly-extending shank b on the guardcasing engages and is held by a spring-latch o, engaging with notches d on the shank.

The guard-casing C is provided with afront face 6 and the flange f, extending rearwardly therefrom.

D is a movable segment of the guard-casing, which is pivotally secured to the main portion thereof and is adapted to be rotated to disclose more or less of the saw.

E is a spring tending to close the segment D, a stop being preferably provided, however, to prevent the segment from entirely closing the opening.

With a guard-casing thus constructed to attach it to the handpiece of the engine it is simply necessary to slip the shank 1) into the socket a and adjust it to a point where the tool will run free of the casing and yet will be guarded by the annular flange f. The instrument may now be used in the mouth of the patient, the operator placing it in the proper position to Work upon the tooth, and as the segment D is held in its closed position by spring-pressure as the tool is forced to its work it will automatically open. At the same time all danger of the tool coming against any'other part of the mouth or the tongue of the patient is completely avoided.

I In Figs. 3 and at of the drawings I have shown a construction in which the casing is formed of two movable segments D and D, pivoted together and to the supporting-shank b, and this, as well as other slight modifications of construction, may be made Without departing fromthe spirit of my invention.

The object of having the casing adj ustably secured to the handpiece is to admit of its being used with various tools the shanks of which may be of different length.

' What I claim as my invention is 1. The combination with the handpiece of a dental engine, and a rotary tool therefor, of a guard-casing for said tool, and carried by said handpiece and a rotary movable segment secured to said casing, adapted to vary the size of opening through which the tool operates.

2. The combination with the handpiece of a dental engine and a rotary tool therefor, of a surrounding guard-casing for said tool, secured to said handpiece and provided with a movable segment and a spring tending to close said segment.

.3. The combination with a handpiece of a dental engine and a rotary tool therefor, of a surrounding guard-casing for said tool, provided with a movable segment and a spring tending to close the same, and a shank to which said casing is attached, longitudinally, adjustably secured to said handpiece.

4. The combination with the handpiece of a dental engine and a rotary tool therefor, of a guard-casing for said tool comprising two segments, a shank to which said segments arepivoted, adj ustably secured to said handpiece, and a spring tending to close said segments.

In testimony whereof I affix my signature in presence of two witnesses.

v FRANK F. HOYER. Witnesses:

W. R. GIBSON, M. E. MILLER. 

